I would differ slightly, by asking if it's possible to contend with fate or free will and succeed? Mon-El, no question, is something that Superman could have achieved, and Brainiac eventually does. However, Krypton and Luthor are intertwined, if you will. The destruction of Krypton gives birth to Superman, and one would have to ask, as it's been raised more than once, what would Luthor be without Superman to despise? Can you save someone from himself?

Pre-Crisis, Krypton's doom is something that seemingly must happen. The Green Lanterns could not save Krypton, and on the occasions where Superman could or was successful in staving off Krypton's fate, the result was always somehow worse than if the Planet survived. . . if I recall correctly.

In terms of Luthor, didn't Maggin write a story where Luthor finally sees the error of his ways and reforms, though many years in the future?

Mind you, I'm not contending with Superman failing as stated, moreso, I'm intrigued by the situations that even his abilities won't allow him to surmount: fate, chance, and free will.

Remember the episode of Justice League where the Justice LORD version of Superman ended up frying Luthor?

Luthor told Superman that he wasn't a hero without a villain and that it was his own ego that kept him from stopping Luthor for good, not the law, not the will of the people. He also told Superman that he secretly loved the cheering fans, the swooning women, the kids looking at him as a hero and that without a villain he is nothing.

Luthor then told him to arrest him, he will beat the rap and start it all over again. Justice Lord Superman then turns on the heat vision...

But Luthor made a valid point: what IS hero without a villain? However the converse is also true: what is a VILLAIN without a hero?

Transformers: Beast Wars: Optimus PRimal gets blown up at the end of Season 1 and Megatron and his crew rather easily defeat the Maximals until a restored Primal comes online and routs them. Though Predacon Megatron was enjoying the win at first I bet he was secretly happy that Primal returned.

Transformers Armada: (horrible show) Optimus sacrifices himself and is destroyed. Megatron actually got bored and was beating the Autobots with ease and lamenting how it was once a challenge. Optimus gets restored, drives Megatron away with a salvo and Megatron is laughing with delight that his enemy is back.

Batman and the Joker: Batman refuses to kill, even the Joker. Joker knows this and keeps coming back to get his jollies and tormenting Batman with new crimes and killing sprees. Batman still won't kill him so Joker keeps coming back for more. In the Batman Under the Red Hood movie he indicates that if he starts killing his enemies even once that he will never stop and refuses to cross that line even if it means Joker constantly returns and kills again and again.

Batman the Killing Joke: both comic and movie at the end it is only Batman laughing and the implication is that he was laughing and strangling Joker at the same time.....but clearly Joker still lives.

But does Batman secretly want a returning villain like the Joker to match wits with? Seems unlikely given he has a rather large Rogues Gallery that includes Rha's Al Ghul.

Green Lantern vs Sinestro: all the times Sinestro should have been killed in recent years and wasn't because both Hal and Sinestro are needed to team up to face many of the threats that have occurred. This is despite the fact that Sinestro infected Hal with Parallax. These two are frenemies but given the opportunity I could see one of them finally killing the other.